 |
|
|
|
|
|
|
|
|
|
|
|
|
| q |
There are two samples, each has six measurements of wind
speed. The
|
|
|
first sample measures a wind speed variance of 10
(m/sec)2. The second
|
|
|
sample measures a 6 (m/sec)2 variance. Are these two
variance
|
|
|
significantly different?
|
|
|
Answer: (1) Selected a 95% significance level (a = 0.05)
|
|
|
(2) H0:
s1 = s2
|
|
|
H1:
s1 ¹ s2
|
|
|
(3) Use F-test
|
|
|
F =
10/6 = 1.67
|
|
|
(4) This is a two-tailed test. So choose the 0.025 significance
areas.
|
|
For n1
= n1
= 6-1=5, F0.975=7.15.
|
|
|
(5) Since F< F0.975, the null hypothesis
can not be rejected.
|
|
|
(6) Variance from these two samples are not significantly different.
|